This improved invention relates to lens blanks, and to a method for making a lens and more particularly to a system embodying the cold flow compression molding of a lens between a pair of mold/cavities using a preformed lens blank of thermoplastic material, and of predetermined configuration. The system is particularly applicable for use in house by the optician, optometrist and/or ophthalmologist. The method and apparatus further do not require the use of skilled technicians, and reduces the cost of prescription lenses since they are created substantially defect free, eliminating the need for any middle men, such as a laboratory or lens factory. Moreover, the lens can be fabricated quickly in minutes, so that the patient or customer can be fitted with a pair of prescription glasses in virtually no time, and certainly less time than it takes for an eye examination.
Heretofore in the industry, lenses were traditionally fabricated in a distant wholesale laboratory. A patient or customer has first an eye examination, and then orders new lenses based on the eye examination, and then he must return a week or so later to receive and be fitted with a new pair of glasses with the laboratory fabricated lens. This procedure is not only very time consuming, but also expensive. At times errors are made in the prescription. In such cases, yet another visit is required or the lenses must be returned to the laboratory for further corrective measures or an entirely new set of lenses fabricated, with resulting delays and expense.
Within about the last ten years there has been a trend toward development of the so called eyeglass "Super Stores" or "one hour" laboratories. These types of stores are very expensive to run and operate. They require a huge inventory of blanks, and employ highly trained technicians to operate complex lens grinding machines and other finishing apparatuses required to complete all types of prescription lens.
Furthermore, these "Super Stores", to be profitable, require a constant stream of customers as they promote "one hour" service, and generally have highly paid technicians just waiting for orders to keep their machines operating at full capacity.
As a result of this phenomenon, most opticians, optometrists and/or ophthalmologists are losing their customer base and have had their earnings seriously eroded.
More recently, however, there has been an attempt to introduce the "mini-lab" to the optician/optometrist, and/or ophthalmologist. This is a direct attempt to bring in-house "one hour" capability of making lenses directly to the source who fills the prescription lens.
One such organization in this field was Vision Sciences of Monrovia, Calif., who marketed an in-office lens casting system employing a choice of resins, such as Master Cast 1.5 clear resin, Master Cast 1.50 with UV protection and Master Cast 1.56 High Index with UV protection. Such a system was capable of casting plastic lens whose styles include single vision, progressive bifocals, flat top 28 or 35 bifocals, Round Seg 28 bifocals, flat top 7.times.28 bifocals, flat top 7.times.28 trifocals; and whose base curves are 2,4,6 or 8 with lens diameters of 72 mm, 75 mm and 80 mm. This Formalens system was of modular design and embodied a generally large work station incorporating a number of mold storage modules, a resin dispenser, and casting and curing stations. With cure cycles varying from 3 to 16 hours, the customer or patient must usually return a second time to complete his order for new prescription lenses. Such an overnight timetable in reality reduces such "one hour" service to "one day" service at best.
In addition, a deionized, laminar air flow unit is necessary in order to provide a static-free, dust-free area in order to ensure fabrication of clear, sharp spectacle lenses. Such "Method of Choice" plastic lens production systems for office use as marked by Vision Sciences were known as Model numbers 2001 and 2002 and ranged in cost from about $27,000 to $63,000, excluding the cost of optional equipment, such as ultrasonic cleaning units and extended range molds that include higher powers and a wider selection of adds.
Such min-labs are not only very expensive to purchase, but their cost of operation is also costly. In fact, the casting process is laborious since about half of same is "science" and half is "art". As a result, the scrap rate or rate of rejection is very high. This is due to the fact that the optician, optometrist, and/or ophthalmologist is not an expert manufacturer, and lacks sufficient skill and training despite the fact that all purchasers of such Fomalens System had to undergo a lengthy and expensive training program at Vision Sciences' home office in order to be able to properly operate the system. It is so complex it required a 100 page operator's manual in order to learn how to operate the system. All of these disadvantages have over the last few years brought on a definite need for an improved and better system.
Another similar type lens casting system was marketed by Techna Vision of San Diego, Calif., but this company is no longer believed to be in business either. It is believed that the casting systems developed by both Techna Vision and Vision Sciences involved considerable difficulty due to the complexities of the casting systems employed. The experiences have been negative and, in reality, failures.